Field of the Invention
The present invention relates to medical devices. More particularly, it relates to devices used to aid in the insertion of hemostatic materials into a wound after completion of a percutaneous procedure. It also relates to devices used for precisely locating internal punctures in arteries, veins, internal organs and the like.
Numerous medical procedures involve percutaneous insertions into a vein or artery. Among the more common are cardiac catheterization, intra-aortic balloon pumping (IABP) and percutaneous transluminal coronary angioplasty (PTCA). When such a procedure is completed, the catheter and/or sheath is removed, leaving a wound that must be repaired. The wound consists of a skin puncture, an arterial or venous puncture and a channel through the patient's tissue connecting those two punctures.
Traditionally, repair was accomplished either by application of pressure for extended periods of time or sometimes by suturing. More recently it has been found that insertion of hemostatic materials, especially collagen plugs, against the outside wall of the affected artery or vein produces better results, more rapidly and with less discomfort to the patient. One such procedure, and a device for practicing that procedure, is described in U.S. Pat. No. 5,391,183, assigned to the assignee of this application, the contents of which are incorporated herein by reference.
Since clots within the blood stream are extremely undesirable, it is important that the insertion of collagen be done in such fashion as to avoid forcing it through the arterial puncture. Several devices have been developed in an attempt to accomplish this objective. For example, U.S. Pat. Nos. 4,744,364, 4,852,568, 4,890,612, to Kensey propose an umbrella-like structure permanently placed in the vessel to seal the arterial wound from the inside. Another approach is described in U.S. Pat. No. 5,108,421 wherein a balloon is placed inside the arterial lumen, expanded until it is larger than the wound, and then pulled back against the wall of the artery to act as a temporary seal and stop to prevent further plug advancement.
A different approach to preventing entry of collagen into the artery can be found in previously noted U.S. Pat. No. 5,391,183. That patent teaches use of a collagen guide sheath which is larger in diameter than the vessel puncture. The sheath, because it is oversized, cannot pass through the vessel puncture so as to enter the lumen. Upon insertion of such a guide sheath, the physician can tell when the distal end reaches the vessel wall simply by tactile sensation. The collagen, which is inside the sheath, is then held in place at the outer wall of the vessel while the sheath is withdrawn.